Urine Immunoassay Identifies Novel Lupus Nephritis Biomarkers

The 5 biomarkers were significantly elevated in active lupus nephritis compared with inactive lupus nephritis and healthy control patients.

Researchers have identified low-abundance urinary biomarkers that are potentially useful for diagnosing lupus nephritis (LN), according to a new study published in Arthritis & Rheumatology.

The researchers identified these biomarkers using a new technique, an electrode-coupled immunoassay with an electrochemiluminescence (ECL) signal, that is more sensitive than traditional ELISA or antibody-based arrays.

Using a preexisting 40-plex ECL panel, Chandra Mohan, MD, PhD, from the Department of Biomedical Engineering at the University of Houston, Texas, and colleagues analyzed 48 human urine samples from 2 independent cohorts each consisting of 8 patients with active LN and 8 with inactive LN and 8 healthy control patients.

They found 17 urinary proteins that were elevated in the active LN samples compared with samples from patients with inactive LN and healthy control patients in 1 cohort, and 9 that were similarly elevated in the other cohort. From these, the investigators chose the cytokines interleukin (IL)-7, Il-12p40, and IL-15 and the chemokines IP-10 and TARC for further validation. These 5 biomarkers were undetectable by ELISA.

The investigators developed a custom 5-plex ECL panel, which they used to validate the results from the initial 40-plex screening panel.